RHS head valve train??

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highwaystar

highwaystar

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Hi Guys,
I am looking for helpful information on good rockers for these heads. I have a set of 1.6 ratio PRW rockers. There seems to be a big problem with clearances. I talked to one fellow and he said almost all the RHS heads are going to create the need to dremel clearance on the rocker gear. I will enclose pix of the heads. I do not have the shafts bolted down, but there would be clearance issues regardless. Will the clearancing weaken the durability of these rockers? These are the 205 valve RHS heads with slight porting. Not sure of the spring diameter size, just that I can go up to a 580- 590 lift cam profile. Are there better rockers out there with better clearance for street/strip?
Also, I have heard the need for special head stud kits, Who has them on here.? This will be for a small 340 stroker.
 

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This is why we use Beehive springs! Every rocker arm I've tried on the RHS heads with our valves will hit a typical 1.45 retainer.
 
I second the beehive springs. Comp Cams has a variety that should cover most needs. Might have to get creative with +.050" locks or retainers to adjust pressures.

What are your installed height and closed/open pressure requirements?

As for head fasteners, I don't know about studs, but ARP has a bolt set specifically for RHS heads - 144-3606.
 
Will the beehive springs miss this rocker gear, or will there still need to be some clearancing.
 
They should provide plenty of room. I have Harland Sharp rockers (which are probably thicker in that area because they are aluminum), with a set beehives that take a 1.185" retainer, and no clearancing. I think the biggest beehive retainer is 1.320", which would provide over .060" more clearance over yours. But it all depends on what springs you end up with. There are beehives with smaller retainers also.
 
yep. I got my heads from Brian and he installed beehive springs. I have hughes 1.5 roller rocker arms...this is on a 318.

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Mopardude,I am curious.How do those heads look,quality wise?(The casting quality)
 
abodybomber, they look good to me! lol, but really, i didnt see any major casting flaws, but wasnt really lookin too hard for em....Brian, crackedback, 1wildncrazyguy, maddart and a few others would be able to tell you...
 
I've seen pretty good casting and machining quality also. Some castings do have a little bit of roughness/flashing/boogers, whatever you want to call it, in the bowl area just behind the valve guide. Just a little. But it's nothing that can't be touched up, if rules allow, or totally eliminated with regular bowl porting or polishing.
 
Thanks,Locomotion.Looking at Mopardudes pictures,line of sight looks really good.Just curious if they flow the numbers as advertised.
 
The valve tip is just about flush with the top of the retainer. This is causing some of the problem. If you machine the spring seat down and use a keeper to move the retainer down(and still keep your installed height on the spring the same), it will help out a lot. Plus you can use a slightly smaller dia retainer, the ones you have are as big as the springs themselves.

Beehives will make way for a lot of room, but when you need a dual spring, you have to make it work. I have built a lot of the heads too, and have run 1.45" springs without issue or grinding on the rockers.

Sometimes if you dont have the rocker perfectly centered on the valve they will hit.
 
sounds like beehive springs would be cheaper than new rockers. I looked up my paper work on these and the springs were good to 570 lift. not sure of installed height or pressures. I would like to run a solid lift cam close to the 570-580 that Brian has reccomended in other forums. Any recommendations on part # for these springs and retainers. Do I need to machine the seats down, if I switch to the bee hive springs?
Thanks for the info guys,
T.J.
 
I'll be monitoring this thread, great info for my upcoming build been thinking about the RHS heads. I was wondering why beehive springs were necessary, thanks.:blob:
 
I have those same rockers 1.6 and i had to clearance them for eddy heads, but when i put the harlan sharps on no problem.
 
ou812 said:
this is why we use beehive springs! Every rocker arm i've tried on the rhs heads with our valves will hit a typical 1.45 retainer.
Click to expand...

We have Comp 26995 Beehives with a .584 tight lash Bullet solid. The other benfit is quite a bit of weight taken out of the valve train with Beehives, FWIW.
 
2010MoparNatsandChenowethcontestengine037.jpg
Here is another method if you want to spend the time.

RHS LAX head with the stud bosses drilled and tapped for 7/16 studs. Scorpion Chevy rockers, .150" long valves, Jomar Mopar Magnum stud gridle, 1.55" diameter springs, 1.900" IH, .750" lift.
2010MoparNatsandChenowethcontestengine050.jpg
 
The castings themselves look clean, no issue there.

It is a bummer that they will not take a common spring/retainer diameter OD, it seems you have to buy the $280 springs and then the matching retainers for another $60-$100.

They are also quite short on inst height, hence the pop up locks and or retainers that most use...along with machining to the spring seats/pads to get more on that end.

otherwise, they make good numbers.

It's app specific.
 
I was reading this thread and got concerned, I have a set of RHS heads from Hughes with regular Hughes 1110 springs, 1.440" OD. Hadn't heard you had to run the beehive style with them.

So I bolted up a set of the stock 273 style adjustable rockers and found that they cleared just fine. Not by a lot, but there's a visible gap. Of course those are 1.5:1 ratio rockers, and of course most of the stock stuff was actually a little shy of that, but they do clear those springs in case anyone wanted to know...
 
Comp Cams sells std. length as well as +.100 1.92" and 1.625" stainless valves for these heads. I don't recall if they have bigger diameters at the moment. So the +.100" valves with +.050" locks or retainers will help with installed height options. But then the installed height can affect the rocker arm contact and sweep across the tip.
 
72bluNblu said:
I was reading this thread and got concerned, I have a set of RHS heads from Hughes with regular Hughes 1110 springs, 1.440" OD. Hadn't heard you had to run the beehive style with them.

So I bolted up a set of the stock 273 style adjustable rockers and found that they cleared just fine. Not by a lot, but there's a visible gap. Of course those are 1.5:1 ratio rockers, and of course most of the stock stuff was actually a little shy of that, but they do clear those springs in case anyone wanted to know...
Click to expand...

really...if all was correct in the design, it most likely the larger after market rocker....but if u say the 273 rocker hits a 1.437-1.45 spring, then it could be the head design/copy is off some or based on a shorter spring/stem height..
 
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